Editor’s note • This story was funded in part by a grant from Solutions Journalism Network to examine ways Utah businesses and individuals are working to reduce the state’s air pollution problem.
Is it possible to build affordable yet highly energy efficient homes?
Airtight homes not only reduce greenhouse gas emissions that contribute to climate change and air pollution, but they can also reduce energy costs, which pose a higher burden on low-income households.
So far, it’s mainly been the wealthy who have sought to build homes that are more efficient than what the Utah code demands. But that may be changing.
As Utah faces a crisis in affordable housing and housing developers grapple with their growing role in the Wasatch Front’s poor air quality, Habitat for Humanity Salt Lake Valley wants to create housing that sells for well below market rates and is low on energy costs. It has built one of 20 planned twin homes on former baseball fields in a housing development idealistically called Field of Dreams in Kearns, at 5803 S. 4270 West. Another is under construction.
“The concept was, could we build a house that was so energy efficient and affordable at the same time? Could we build a house that only used $1.50 a day in total utility costs?” says Edward Blake, CEO of Habitat for Humanity Salt Lake Valley.
The answer is yes, in theory. But not without some struggles along the way.
[Read more: Salt Lake City to building developers: Go electric]
With homes built largely by volunteers using technology that is new to Utah, the process has been slow, frustrating homeowners who have complained of mistakes.
Still, the first homes are more efficient than the Utah code, they cost $650 a month, plus a homeowners association fee, selling for between $200,000 and $230,000 depending on the size. And they could cost less than $2 a day for the smaller 1,500-square-foot units to heat and cool. This is doable for a family of four making around $40,000 a year.
“I’m glad to have a low payment and put my kids in activities and not be house broke,” says Lillith Bear, who moved into her 1,500-square-foot home with her husband and three children last March. “I still think we made the right decision even though it wasn’t the experience we expected.”
The experiment
Habitat for Humanity is a global nonprofit with local affiliates throughout the country whose mission is to eliminate poverty and homelessness by building affordable homes and repairing homes for working families.
The Salt Lake Valley organization averages building four homes a year, Blake says, using mainly volunteer labor. Habitat raises money for the land and material.
To qualify for a Habitat for Humanity home, buyers must make between 30% and 60% of Salt Lake City’s annual median income of $80,000 for a family of four, or between $24,800 and $49,620, according to federal guidelines. And each co-signer must volunteer 225 hours to Habitat projects.
In exchange, they get a 30-year mortgage with no interest (Habitat lends the mortgage loans to the families).
By comparison, a three-bedroom apartment would cost $1,518 for rent and utilities in Salt Lake County, according to the National Low Income Housing Coalition. Habitat homeowners start to earn equity in the fifth year in their home.
In 2014, Habitat started working with University of Utah architecture professor Jörg Rügemer with the goal of reimagining affordable housing with energy efficiency in mind.
He designed two-story twin homes instead of Habitat’s standard one-story home in order to reduce the costs for the foundations and roofs and to provide better energy efficiency by reducing energy loss.
He also employed passive home design principles, which call for superinsulation and airtight construction to prevent loss of conditioned air, an energy-recovery ventilator that keeps the air fresh and heats or cools the incoming outdoor air with the outgoing air, and a floor plan to take advantage of solar heat from the south, according to the U.S. Department of Energy and the Passive House Institute US.
The homes’ heating and cooling systems are highly efficient, too, with an instant water heater, hydronic radiant floor heating system on the ground floor that sends hot water through tubing laid in the floor, and a ductless, electric mini split heat pump for heating and cooling, which absorbs heat and transfers it. They are more efficient than traditional ducted systems (“Forced air is a dinosaur; we shouldn’t use that anymore,” says Rügemer) because they avoid the 30% of energy loss that can come from ductwork, according to the U.S. Department of Energy. The homes are also planned for raised vegetable gardens using a drip irrigation system.
(Christopher Cherrington | The Salt Lake Tribune)
The first two homes in Kearns were built with an efficiency rating, known as a HERS (Home Energy Rating System) score, of 39. That means their energy consumption is modeled at 61% less than a standard new home in the United States. In Utah, new homes built since 2016 must have a HERS score between 69 and 65. The lower the score, the more efficient and the more saved on utility bills.
Blake says the costs of adding energy efficient systems was $7,000 per home, or $14,000 per building. “That’s not a significant amount that we shouldn’t be building this way, especially for the return we get for how efficient the home is,” Blake says.
Blake and Rügemer agree the prices will drop as more builders use the products. “You can get to a point where it’s not that much more expensive anymore. Today in Germany, passive [home components] don’t cost any more than standard components. It took 25 years but eventually we got there,” Rügemer says. “It requires a change of politics. It requires strong collaboration. It can be applied in the affordability market for sure and it should be.”
But Habitat and Rügemer didn’t see eye to eye and they have since parted ways; Rügemer says he had concerns about Habitat’s building methods and Blake says Rügemer’s design elements were too expensive.
The architect says the Field of Dreams homes were actually designed to be 80% more efficient. “The failures were in the execution of the building. That is completely in Habitat’s hands,” he says.
While acknowledging that volunteer labor can result in mistakes that have to be fixed, Blake says the homes were “under the microscope” by inspectors who ensured they were built to code.
“It was definitely one of the very early attempts to have an organization like Habitat jumping on the train of energy efficiency to push the limits with a very low budget,” Rügemer says of their collaboration.
The Field of Dreams homes were analyzed by an energy rating company before the homeowners moved in. One home’s report estimates it would cost $554 a year for heating and cooling, plus $100 a year in service charges. That comes out to $1.79 a day for the total costs, or $1.51 a day without the service charges. The report also estimates the home reduces carbon dioxide emissions by 4.9 tons a year and nitrogen oxides (which contributes to particle pollution and ozone) by 14 tons a year, compared to a national reference home.
The energy audit anticipated the homes would use 19.5 dekatherms of natural gas a year. By comparison, a similar-sized home in Kearns uses 75 dekatherms a year, according to an analysis prepared for The Salt Lake Tribune by Dominion Energy Services, which provides natural gas in Utah. It found that the average 1,350-square-foot home in Kearns was typically built around 1975, when building codes were much less efficient. Rocky Mountain Power didn’t have a similar analysis.
‘The guinea pig house’
While the homes qualify as affordable, the homeowners say their bills aren’t as low as advertised; one said her average from August to January was $94 a month, or double the model.
In some ways, that is to be expected, since each homeowner will use energy differently than what is modeled. For example, the model assumes seven-minute showers and keeping the temperature in the low 70s on sunny winter mornings, according to Rügemer.
But the homeowners believe construction problems have led to inefficiencies. Kinsella, who lives on the other side of Bear and didn’t want to give her last name, said her home is not as airtight as advertised because dirt “pours in” from the ongoing construction. Her main floor has a large crack in it, so she worries the radiant flooring was installed incorrectly. She said her mini split air source heat pump didn’t work for months.
“I don’t understand how this program thinks they’re helping out families. How is it giving someone a hand up if they’re getting all these problems?” she says.
Blake says Habitat will fix the cracked floor, and it replaced the mini split heat pumps that may have malfunctioned because they likely weren’t designed for a twin home. A building inspector with Greater Salt Lake Municipal Services says the mechanical equipment was installed per code.
“I don’t know how to make them more confident in the building, but we’ll keep trying,” Blake says.
The homeowners, and surrounding neighbors, are also frustrated at the slow pace of construction: Five years lapsed from when the design started to when one twin home was ready for occupancy.
Blake estimates another three years to finish the rest, though homeowners are skeptical since only one home has been built and the second is under construction. The site required a zoning change; the exterior walls are new to Utah, called structural insulated panels, and had to be built in Montana. Blake says the building methods also posed a learning curve to county inspectors.
“They brought their people out and trained them on our type of building,” he says. Using volunteers and seeking money for each home delays the process, he says.
Future homes, which will include 700-square-foot basements and could cost $230,000, will use even more insulation by using an airborne sealant to plug holes as thin as a human hair and up to a half-inch thick.
Bear applied for the Habitat program because her family was living in a 500-square-foot apartment and needed more space, but they were shopping for a home in Utah’s hot housing market and couldn’t find one they could afford on her husband’s salary as a delivery truck driver. Homes under $200,000 were too far away from his job or needed major renovations. She remembers looking at one house selling for $150,000 that was tilting and the sellers were “kicking garbage out of the way so we could even get in. … We weren’t necessarily looking for glamorous but we also didn’t want it to be unsafe or moldy.”
She says she ended up paying about $50,000 more for the Habitat home than she was told she would have to pay (Blake notes the first houses have already increased in value and are worth $250,000). Bear is enjoying having her own space — being able to pick out paint colors and have a dishwasher. She’s looking forward to the end of construction and getting the promised green space for her children to play in.
“It’s been affordable and I think they’re going to keep getting better,” Bear said. “We are for sure the guinea pig house.”
